Ampeg PR-410HLF Crossover Bulbs Needed!

Discussion in 'Amps and Cabs [BG]' started by Tube Amps Rule, Sep 21, 2016.

  1. Hey all -

    Has anyone ever been able to source the bulbs on the crossover pictured?

    Ampeg Tech Support was not able to help.

    Both are blown and the tweeter is not working.

    Thanks in advance!


    Last edited: Sep 21, 2016
  2. Bulbs? Or are they Fuses? I don't know for sure.
    I've seen bulbs used for current limiting and maybe that's what is happening here?
    Seems odd though to do that in a speaker circuit. It is Ampeg however.
    If they are fuses and you asked Ampeg for bulbs, that may explain why they couldn't help.
    Maybe try them again and ask about those two little glass thingies on the crossover board.
    It looks like the upper one is labeled JWOPT1 and maybe the other is JWOPT2, you might ask Ampeg about those designations.
    I'm surprised they weren't more helpful.

    -edit- Now that I look at it closer, I see a JWOPT2 to the right (vertical orientation in the pic) and that looks to be just a jumper wire JW= Jumper Wire? The JWOPT1 appears to be just below the top glass thingy and looks like a jumper wire. I'm back to guessing the glass thingies are fuses.
  3. They are bulbs used to take the current from your tweeter, almost all cabs use them. And if you are really cranking it sometimes you can see cabs glow. :woot:
    Most of them you can get at auto parts stores, but I could not find a number for them. :banghead:
    Maybe @beans-on-toast will know? He knows Ampeg. :help:
    Old Garage-Bander likes this.
  4. beans-on-toast


    Aug 7, 2008
    It's a limiting light bulb.

    The schematic indicates that it is a 36V bulb but there isn't a part number, that would be on the bill of materials (called BOM). I would call customer service back and ask for the crossover bulbs for your speaker cabinet. If that doesn't pan out, PM Hodgy here on TB for assistance.
    wave rider and S-Bigbottom like this.
  5. Vintage-Blue

    Vintage-Blue Gold Supporting Member Commercial User

    Feb 13, 2008
    Cincinnati, OH
    Owner, Vintage Blue (repro cabinets)
    The BOM lists the part number as 49-205-01 (36V 1.5A PC LAMP). They should have them in stock.
    BassmanPaul and beans-on-toast like this.
  6. bassmanshoe


    Nov 24, 2011
    Portland OR
    same bulb is used as a dome light in some Fords from the 90s-00s. Good auto parts guy can match it by eyeball
  7. beans-on-toast


    Aug 7, 2008

    Here is the part from a Loud service center in Belgium, shows that they sell it. Out of stock though.
    Last edited: Sep 23, 2016
  8. Thank you kind sir for the info.
    I guess it a became a slo blo, no glow, where'd the music go? kind of thing. :whistle:
    S-Bigbottom likes this.
  9. beans-on-toast


    Aug 7, 2008
    These bulbs have a tungston filament. The resistance is low when cold and increases as the current increases. This way, the bulb acts as a current limiter. Although they are commonly used in crossovers, bulbs aren't the best approach. The problem is, it would be better if they reacted faster to surges but they are cost effective.

    On some cabs you can see the bulbs flashing. If the cab has a rheostat to control the level of the high frequency driver, turn it down if you see the lamp flashing.

    On this model, you see four spaces for bulbs. The early revision used four 12V 1A bulbs. The two 36V bulbs proved better.
    Old Garage-Bander likes this.